Apparatus for indicating differences in angular velocity in rotating members



Aug. 19 1924. 1,505,515

' e. WIRRER APPARATUS FOR INDICATING DIFFERENCES IN ANGULAR VELOCITY IN ROTATING MEMBERS Filed Sept. 12 1923 2 Sheets-Shoe! l .3 g a? U Q6 3 341% I M 7 i 1 11mm y/ 4 mmm 5?,

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vA,\ 2 g 3 1 wuamtoz Patented Aug. 19, 1924.

' .UNITED STATES PATENT OFFICE.

GOTTFBIED WIRIQER, OF PLAINFIELD, NEW: JERSEY, ASSIGNORTO INTERNATIONAL MOTOR COMPANY, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

APPARATUS FOE INDIGATING DIFFERENCES IN ANGULAR VELOCITY ROTATING MEMBERS.

Application filed September 12, 1923. Serial No. 662,360.

.To all whom it may concern;

Be it known that I, Go'rrrmnn WIRRER, a citizen. of the Swiss Republic, residing in Plainfield, in theState of New Jersey, have invented certain new and useful Improvements in A paratus for Indicatin Difl'erences in Members, of which the following is a speci- Y fication, reference being had to the accom- '1 panying drawings, forming a part hereof.

This invention relates to improvements in apparatus for indicating diflerences in angular velocity in two rotating members. The principle applied in the improved apparatus is that involved in the inter-action of three discs having rolling contact and arranged to rotate in a common plane with their axes in the same plane, the two outer discs being mounted on fixed centers, the

middle disc being capable of displacement in a direction transverse to the plane including the axes of the discs. If the angular veloci ty of the two outer discs is exactly proportionate to their diameters, the middle disc 95 which is driven, by frictional contact with the outer-disc'will -rotate without displacement of its'axes. A differential angular velocity between the outer discs, however, will result in a proportionate displacement of the axis of the middle disc. The improved apparatus includes three discs of this nature in which the middle disc is operatively associated with an indicating mechanism whereby suitable indication of the differential angular 6 velocity between the two outer discs may be obtained. Such apparatus is advantageously used to indicate the difi'erence in angular velocity between two rotating gear wheels,

transmission 'drive shafts or any other ro- 40 tating members one of which, under normal conditions, should rotate at a speed proportional to the other. It will be apparent that if the two outer discs are caused to rotate in synchronism respectively with the two rotating members any difierence' in their angular velocity will be shown by the indicating mechanism.

The improved apparatus is particularly useful in testing the teeth of gear Wheels to indicate inaccuracies in the workingfaces of the teeth. It the teeth of one or both of a pair of co-actin gears be inaccuratel formed and one o the pair is rotated wit constant angular velocity the other gear will ngular Velocity in liotating' -with reference to the accompanying drawings illustrating a preferred embodiment thereof in which;

Figure 1 is a view of the apparatus in plan showing the relationship of the parts. Figure 2 is a vertical section taken on the planes indicated by the broken lines 2-2 in Figure 1 and looking in the direction of the arrows. I

Figure 3 is a view in side elevation of the apparatus looking from the left in-Figure 1.

Figure 4 is a view in plan of the indicating mechanismf Figure 5 is a view in side elevation partly in section of the indicating mechanism shown in Figure 4.

Figure 6 is a diagrammatic view of three discs in rolling contact illustrating the principle of operation of the invention.

In the drawings a preferred embodiment of the improved machine has been illustrated wherein the friction discs are caused to rotate in synchronism, respectively, with two inter-acting gears, the teeth of which are to be tested, but it "will be evident to those skilled in the art that the two gears may be readily replaced by devices transmitting rowhich illustrates the principle applied in the improved machine, the three discs X, Y and Z being shown as having rolling contact and arranged to rotate in a common plane with their axes in the same plane. Discs X and Z i are mounted on fixed centers while the mid dle disc Y is floating, that is, its axis is capable of movement in a line transverse to the plane including the axes of theother discs. It will be evident that if discs X and Z are rotated in opposite directions at the same angular velocity, the middle disc Y will-roembodiment to a gear testing machine. Re-

ferring to Figures 1 and 2 a pair of spindles a and b are mounted on relatively movable supports a and b so as to be relatively movable with respect .to each other to accommodate gears g, g of different diameters for testing. Suitable mechanism to effect this relative movement will readily occur to those skilled in the art, and as it forms no part of the present invention,vis not illustrated. Spindle b is formed .with a shoulder 6 adapted to support for rotation on the spindle a sleeye b formed with a flange b at its lower end. Carried with sleeve 6 are friction disc 2 and'gear g suitably spaced by a spacing element 6 The disc and gear are clamped to rotate as one with sleeve 72 by means of the knurled head b threaded onto'the threaded end of sleeve 6 Swinging freely on spindle b is a supporting arm a, balanced by weight 0'. This arm is supported for rotation upon a flange b" integralwith spindle 6. Supporting arm 0 is held in place by nut b and spring washer b. On the companion spindle a the sleeve 0, is rotatably supported upon a flange a integral with spindle a. Sleeve a is formed at its lower end with flange d adapted to carry friction disc at disposed in the same plane with friction disc :1: but out of contact therewith.

. Also supported on sleeve a is the gear 9 in mesh with the gear 9''. Disc (1 and gear '9 are supported in proper position on the flange a by spacing elements a and are rigi ly clamped to rotate as one with sleeve a by means of knurled head a engaging the threaded end of the sleeve a The end of supporting arm 0 remote from its counter-balance wei ht 0' is slotted as at, 0 A spindle c is isposed in the slot 0 and is supported on the arm 0 by flange c. The spindle is retained in the slot in upright position by means of washer a and nut 0. It has a loose fit in slot 0 and is adjustable lengthwise of the supporting arm by means vof the screw 0'. Rotatably mounted on the spindle c is the friction disc :2: which is disposed in the same plane with friction discs 2 and d. The friction disc m is adapted to be maintained in rolling contact with the friction disc at by a spring 8 connected to the bracket 0 on the supporting arm a and the bracket a on the support a. Spring 8 is of such length as to be always under tension and serves to maintain the friction disc 0; always in frictional contact with disc at for rotation thereby.

Secured to the supporting arm 0 midway between the spindles?) and c is a bracket 6 rigidly secured to the arm as by screws 6. One arm of bracket 6 is formed with i a .groove e in which is adapted to reed so as to allow free movement to the indexing'disc 3 in any direction except the vertical and is guided only by the rounded end 7. Normally the slide 7 is adapted to be disposed in the groove in bracket e so that the axis of disc 1 liesin the line including the axes of discs '2: and 2. Slide f is formed with a slot 7" adapted to receive the 'shorter arm 0' of a stylus 0 fulcrumed on the bracket 6 at- 0. The longer arm of stylus 0 extends over the disc :1: and a card or the like It concentric with disc w is adapted tobe clamped to rotate as one therewith bymeans of the knurled head 0 on the spindle 0?. The stylus 0 is so formed as to contact with the card as' will be readily understood.

' The operation of the apparatus is as follows:

Rotary movement is imparted to the rotating bodies to be tested by any convenient means. In testing gears it is preferred to rotate one gear, say the gear g, by hand. Gear 9 being rigid with the sleeve 12 and friction disc 2 will cause the rotation of the said friction disc in the same direction. Being in mesh with gear 9, it will cause that gear to rotate in the opposite direction. As gear 9 is rigid with the sleeve a rotation of the friction disc (1 will be effected.

Disc :21, being always held in frictional engagement with disc d by springs 8, will be caused to rotate in a direction opposite to the direction of rotation of the disc 2 and at a rate proportional therewith. Thus it will be seen that discs :1; and z are caused to rotate in synchronism with the gears. Disc y is disposed between and in frictional engagement with discs w and z and any change in the relative angular velocity of the two outer discs will cause the axis of disc 3 to change its position with respect to the plane including the axes of discs 00 and y as explained in connection with Figure 6. As any change in the position of the axis of the disc y will be transmitted to the stylus 0. A record of the variations in the position of the disc '3 will be indicated on the card It by the stylus. It will be apparent that if the teeth of one or both of the coacting gears be inaccurately will cause it to trace" on the indicator card a record of movement of theaxis of disc 3 and thus an indication of the imperfections ofthe gear or gears will beobtained.

Various modifications may be made in an apparatus designed to operate accordin to the principle hereinbefore described w ile it may be adapted to various purposes besides testing gears and no limitation by the foregoing description is intended except as indicated in the accompanying claims.

What I claim is: 1. In an apparatusfor indicating difierential angular velocity between rotary men bers in combination with two rotating members whose differential angular velocity is to be indicated, other members rotated synchronously with said'members respectively, another member rotated by direct frictional engagement with said second named mem- K bers and means to indicate differential rotation of the first mentioned members by bodily displacement of the last mentioned member.

2. In an apparatus for indicating differential angular velocity between rotarymembers in combination with two rotating members whose differential angular velocity is to be indicated, two friction discs mounted on fixed axes and rotated synchronously with said members respectively, a disc in direct frictional engagement with said first mentioned discs and arranged to be displaced by the effectof the differential rotation of the first mentioned discs thereon and means actuated by such displacement to indicate such differential rotation.

3. In an apparatus for indicating differential angular velocity between rotary members, in combination with two rotary members whose differential angular velocity is to be indicated, three discs disposed in the same plane with their axes lying in the same plane, the two outer discs being rotated synchronously with said members respectively, the middle disc movable transversely of the said plane including the axes of the outer discs andindicating mechanism actuated by the middle disc in its transverse movement. 4. In an apparatus for indicating differential angular velocity between rotary members, in combination with two rotary members whose differential angular velocity is to be indicated, three discs disposed in a common plane with their axes "disposed in the same plane, the two outer of said three discs being mounted on fixed centers and the middle disc being rotatably mounted on a slide the axis of said middle disc being normally disposed in the plane including the axes of the outer discs, a stylus actuated by said slide and a record holding member adapted to rotate in unison with one of the outer discs to be marked by the stylus.

5. In an apparatus for indicating differential angular velocity between rotary members, in combination with two rotary members Whose differential angular velocity is to be indicated, two friction discs rotated synchronously with said members, a third disc rotated by one of said first mentioned discs in synchronism therewith, another disc in frictional engagement with first mentioned two discs and mounted on a slide, a stylus mounted on a pivot relatively stationary with respect to the slide but actuated thereby and a record disc carried with the third disc and in contact with the stylus.

6. In a gear testing machine, two relatively movable spindles, co-acting gears rotatably mounted on said spindles, friction discs mounted on said spindles and rotating in unison with said gears, a supporting arm rotatably mounted on one of said spindles and carr ing two discs in frictional engagement an with their axes in ,a line including said spindle, and means for maintaining one of the discs on the arm in frictional contact with the disc on the other spindle,

the axis of the other disc on the arm being 

